EP0061631B1

EP0061631B1 - A device for packing sheet-like elements

Info

Publication number: EP0061631B1
Application number: EP82102042A
Authority: EP
Inventors: Angelo Bartesaghi
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-03-27
Filing date: 1982-03-13
Publication date: 1985-11-21
Also published as: ES264030U; CA1186706A; ATE16581T1; DE3267504D1; BR8201763A; IT1136965B; US4460169A; EP0061631A1; IT8120764A0; ES264030Y

Abstract

To ensure a uniform formation in packets with a predetermined number of elements, of sheet-like elements, for example, paper handkerchieves, two counter-rotating bodies are provided, presenting movable blades which, cooperate to receive each sheet-like element coming from a feeding group. Each pair of blades lays down a sheet-like element on a packet to be formed, on its turn supported by fins carried by belts or chains vertically moving downward, starting from the counter-rotating bodies and synchronically with the latter, in such a way that the packet to be formed lowers until the desired number of elements is received, and it is then ejected parallel to the axes of the rotating bodies.

Description

The present invention concerns a device capable of gathering sheet-like elements, cut to size and preferably folded, in reciprocal superimposition to form packets, each having a predetermined number of elements. The invention particularly suits for gathering and forming packets of paper handkerchieves or napkins, but it can also be applied to any other use which involves the need of rapidly, exactly and reliably forming packets of sheet like elements, specially of paper.
To carry out the above mentioned operations, downstream of a cylinder for cutting and folding the sheet-like elements, there are provided, according to the prior art, devices capable of receiving said elements, already cut and folded, so as to form a packet. Each packet is divided from the subsequent one by means of a tooth or dividing head, which must follow a relatively complex run to reach a packet separating position and to follow said packet to a station wherein the packet is placed into a container. This packet separating system is not only very complex and a source of drawbacks and limitations in use, but also it is not able to constantly ensure a perfect formation of the packets with the desired number of sheet-like elements and with a perfect alignment thereof. In fact, a higher or lower pressure on the elements in the packet forming station can cause errors in the count of packet elements, while the insertion of a dividing tooth can cause undesired foldings or local tearings of the sheet-like elements.
DE-C-617 222 shows a gathering device having the features defined in the first part of claim 1. The device comprises a sheet delivering means, a pair of rotating elements with blades, said elements having a vertical axis of rotation. The sheets are placed, by the blades of the two rotating elements, on a supporting means moving in synchronism with the rotating elements and the sheet delivering means. This supporting means carries, on a chain and bars, a plurality of packet dividing elements which advance, together with the supporting means, in a horizontal direction, rotating around a horizontal axis. This known device shows drawbacks which drastically limit in particular its productivity and adaptability to different working conditions. In fact a first problem of this prior art device is to obtain a perfect synchronism between the movements of the rotating elements and those of the supporting means. If this perfect synchronism is not reached, packets with wrong count of sheets are obtained, or a sheet can be fed exactly on the packet dividing elements causing a necessity to stop the work.
This last problem was solved in DE-C-617 222 by temporarily tilting the packet dividing elements. However, this solution is incompatible with the very high working speeds reached by these machines which, for instance in the case of paper handkerchieves, may be of the order of 1000 sheets or 100 packets per minutes, i.e. more than 16 sheets per second. At these very high working speeds, the synchronism must be positively ensured to obtain a proper functioning of the machine.
Therefore an object of the present invention is to provide a gathering device, which allows to form packets of sheet-like elements with the highest reliability, both in what concerns the exact superimposition of the elements and in what concerns the number of elements forming each packet, independently, at least within certain limits, from the thickness of each cut and folded sheet-like element, and therefore form the final thickness of the packet. Everything, of course, must be such as to comply with the need of high working speed and productivity as typical of machines performing the cited cutting, folding and packaging operations on sheet-like elements such as paper handkerchieves or napkins.
Accordingly, the invention relates to a device for gathering sheet-like elements, cut to size and preferably folded, in reciprocal superimposition to form packets, each having a predetermined number of elements, said device comprising, downstream of a device feeding in sequence said sheet-like elements, two cylindrical bodies counter rotating in synchronism at opposite sides of the fed sheet elexents each of said bodies carrying a number of radially extending sheet supporting blades to receive a fed sheet element therebetween, and a packet supporting and defining means in the form of a pair of endless belts carrying equally-spaced packet defining fins and movable in synchronism with the cylindrical bodies on shafts having an axis parallel to the sheets in the packet under formation,
characterized in that

-said shafts of the packet supporting and defining means are coaxial with said cylindrical bodies
-said belts are provided with teeth which engage with corresponding teeth on the cylindrical bodies
- said fins are aligned with the blades of a cylindrical body when the corresponding portion of the respective belt is moving around the respective cylindrical body.

It is then possible to reliably obtain a perfect positioning of the sheet-like elements, in relation to the feeding characteristics of the same by the feeding group, and above all it is possible to reliably obtain the formation of a packet having an exact number of sheet-like elements, in that each packet is defined and separated from the adjacent ones by means of supporting fins which move in synchronism and in coordination with the blades of the counter-rotating bodies.
The invention will be now more fully described with reference to a preferred embodiment thereof, as shown in the accompanying drawings, wherein:

Fig. 1 is a diagrammatic side view of a device for gathering and forming packets according to the invention, in a machine for cutting, folding and packaging paper handkerchieves or napkins.
Fig. 2 is a cross-section according to line 11-11 of fig. 1.
Fig. 3 is a partial cross-section corresponding to that of fig. 2 and illustrating the device in another working position.
Fig. 4 is a partial and diagrammatic view of another embodiment of the device.

Referring to the drawing, the device is placed downstream of a known cylinder 10 for forming and folding for instance paper handkerchieves, which sends said handkerchieves 12 to a conveyor 14, moving on rolls 16 and 18. It must be noted that the following description will be made with reference to paper handkerchieves, but it must be kept in mind that the same may apply to any type of sheet-like element to be submitted to the operations that will be described later on.
Said cylinder 10 sends the folded handkerchieves 12 to said conveyor 14 at a determined, constant frequency and said handkerchieves 12 are fed in the direction X at a constant speed too, preferably with the help of an upper conveyor 20 moving on rolls 22 and 24. As it can be seen in fig. 1, a control roll 18 of conveyor 14 is placed upstream the handkerchief receiving device, generally indicated by 26, while a control roll 24 of upper conveyor penetrates into the device 26 to accompany each handkerchief to the position where it is taken by said device 26.
This device 26 essential comprises, as it can be particularly seen in fig. 2, two cylindrical bodies 28 and 30 rotating around horizontal axes 32 and 34 parallel to the direction X from which the handkerchieves 12 come.
Each body 28, 30 has a series of plane and straight blades 36, 38 angularly equidistant and capable to assume, when said bodies 28, 30 rotate in directions Y, particularly the position as shown by 36' and 38' in figs. 2 and 3, where said blades define a horizontal plane to receive, and keep each handkerchief 12 placed on them by conveyors 14 and 20.
Each rotating body 28, 30 is provided with one or more toothed areas 40, 42 with which corresponding toothed belts 44 and 46 engage, said belts moving between the rotating bodies 28, 30 and corresponding toothed transmission rolls 48 and 50, vertically below said rotating bodies 28 and 30. The belts 44 and 46 are provided with a series of supporting fins 52 and 54 externally protruding from the belts, as shown at 52', 54' or 52", 54", and designed to align themselves in order to form a corresponding number of moving planes to receive the packets. For this purpose, fins 52 and 54 are coincident with blades 36 and 38, in that each fin 52 and 54 results to be coplanar to one of the blades 36 and 38 during its rotation around body 28 or 30. Moreover, the distance between fins 52 or 54 of each belt is equal to n times the step between blades 36 or 38, where n is the number of handkerchieves 12 forming a whole packet 56. In this way, the first element of each packet 56 is positively positioned on the supporting fins 52, 54 while the subsequent elements of the packet are positioned one after the other by the blades 36, 38, performing a free movement of extremely limited width, in that the packet to be formed lowers as new handkerchieves are placed on it. Finally, a complete reliability about the number of handkerchieves forming each packet is obtained, in that said number is equal to the number of blades 36, 38 between two supporting fins 52, 54 placed in sequence on the toothed belts 44, 46. Therefore, the formation of the packet takes place with the maximum reliability, as well as with the maximum regularity, i.e. with a perfect alignment of the handkerchief edges, in a way actually independent from the production rate of the machine.
The formed packets 56 lower together with the belts 44 and 46 in the vertical direction Z, until they reach a conveyor 58 which takes them away and sends the same to a downstream packaging station.
Of course, in order that the device can correctly work, it is necessary to have a perfect synchronism and timing not only between the counter-rotating bodies 28, 30 and belts 44, 46, as obtained by construction and engagements of teeth, but also with the handkerchief feeding means and therefore between cylinder 10 and conveyors 12, 20, on one side, and the counter-rotating bodies 28 and 30, on the other side. In fact, when a handkerchief 12 arrives, a couple of blades 36', 38' must be present in the horizontal position to receive the same. Said synchronism can be achieved without difficulty by means of mechanical means connecting the movements of bodies 28, 30 with the movements of cylinder 10 and conveyors 14, 20.
Fig. 3 illustrates the position of device 26 after the bodies 28 and 30 rotated a step with respect to the position of figure 2. As it can be clearly seen, the blades 36" and 38" are going to lay down a handkerchief 12 on packet 56 which has to be formed, said operation occurring with the maximum of precision and with a handkerchief free run, from blades 36" 38" to packet 56, which is reduced at a minimum.
Specially in case of sheet-like elements 12a of a big size, for instance paper napkins, it can be advisable to have rotating bodies 28a and 30a with longer blades 36a and 38a. In this case, in order to avoid interferences and to better guide each sheet-like element 12a in its run, the embodiment illustrated in fig. 4 is optionally proposed, in which the blades 36a remain parallel to themselves along the whole run to support the elements 12a, as it is indicated in the sequence 12a, 12a', 12a", and 36a, 36a', 36a" of figure 4. This result can be obtained for example by pivoting each blade 36a to the body 28a as indicated by 60 and by stressing said blade with a spring 62 against a clamp 64 defining its radial position. A cam follower 66 is placed at the inner end of the blade and glides in a fixed guide 68 which allows the blade 12a to remain parallel to itself, as illustrated.
As already mentioned, the invention can be used not only for packaging different sheet-like elements and the principles of the present invention can be achieved also by submitting the illustrated and described embodiments to several modifications and changes, without departing from the scope of the present invention, as defined in the attached claims.

Claims

1. A device for gathering sheet-like elements (12), cut to size and preferably folded, in reciprocal superimposition to form packets (56), each having a predetermined number of elements (12), said device comprising, downstream of a device (14-24) feeding in sequence said sheet-like elements (12), two cylindrical bodies (28, 30) counter rotating in synchronism at opposite sides of the fed sheet elements, each of said bodies carrying a number of radially extending sheet supporting blades (36, 38) to receive a fed sheet element therebetween, and a packet supporting and defining means in the form of a pair of endless belts (44, 46) carrying equally-spaced packet defining fins (52, 54) and movable in synchronism with the cylindrical bodies (28, 30) on shafts having an axis parallel to the sheets in the packet under formation, characterized in that

-said shafts of the packet supporting and defining means (44, 46) are coaxial with said cylindrical bodies (28, 30)

-said belts (44, 46) are provided with teeth which engage with corresponding teeth (40, 42) on the cylindrical bodies (28, 30)

- said fins (52, 54) are aligned with the blades (36, 38) of a cylindrical body when the corresponding portion of the respective belt is moving around the respective cylindrical body.

2. A device according to claim 1, wherein the axis (32, 34) of said cylindrical bodies (28,30) is horizontal and wherein said fins (52, 54) act both as packet-defining and as packet supporting means.

3. A device according to claim 1, wherein said blades (36, 38) have gaps in the length thereof for the passage of the packet supporting afd defining means.

4. A device according to claim 1, wherein said belts (44, 46) are replacable resilient belts.

5. A device according to one of the preceding claims, wherein said blades (36, 38) are movable on said counter-rotating bodies (28, 30) and wherein cam means (66, 68) are provided to define a blade trajectory such as to keep the blades parallel to each other at least in the section where said sheet-like elements (12a) are received, supported and displaced. (Fig. 4).